From: Will Deacon <will@kernel.org>
To: tangzhenhao <tzh18@mails.tsinghua.edu.cn>
Cc: iommu@lists.linux-foundation.org
Subject: Re: [PATCH] drivers/iommu: fix a null-ptr-deref bug in msm_iommu.c
Date: Thu, 10 Dec 2020 09:13:27 +0000 [thread overview]
Message-ID: <20201210091326.GA9633@willie-the-truck> (raw)
In-Reply-To: <20201206094351.47860-1-tzh18@mails.tsinghua.edu.cn>
On Sun, Dec 06, 2020 at 01:43:51AM -0800, tangzhenhao wrote:
> At line 600 in drivers/iommu/msm_iommu.c, the ret-val of kzalloc should be checked to avoid null-ptr-deref bug.
There's no need to mention the line number of the file name in the commit
message -- that information is already available in the diff. Instead,
please try to describe the problem that you're solving.
Have a look at Documentation/process/submitting-patches.rst.
> Signed-off-by: tangzhenhao <tzh18@mails.tsinghua.edu.cn>
> ---
> drivers/iommu/msm_iommu.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index 3615cd6241c4..e3c576e5babb 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -598,6 +598,10 @@ static void insert_iommu_master(struct device *dev,
>
> if (list_empty(&(*iommu)->ctx_list)) {
> master = kzalloc(sizeof(*master), GFP_ATOMIC);
> + if (!master) {
> + dev_err(dev, "Failed to allocate IOMMU context bank instance\n");
No need to print an error here -- kzalloc should be plenty noisy enough
if an atomic allocation fails.
> + return;
Hmm, and then what? We haven't propagated the error, so how much further do
we get?
Will
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prev parent reply other threads:[~2020-12-10 9:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 9:43 [PATCH] drivers/iommu: fix a null-ptr-deref bug in msm_iommu.c tangzhenhao
2020-12-10 9:13 ` Will Deacon [this message]
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